(e.g. craving chips because you need salt)
It’s often said that we crave certain foods (chips or chocolate) because that’s what our body needs. What are your thoughts on this?
Firstly, just about everyone gets food cravings. They are hard to predict and even more complex to understand, but research over the years has shed light on how everything from genetics to emotions to the environment can play a role in determining what foods we like and feel compelled to devour.
To say that we crave certain foods because that’s what our body needs is a bit generic and naive. It’s important to understand that people’s likes and dislikes, and the kinds of food they purchase and eat at any given moment are impacted by a lot of variables. Some of those factors might still be unknown, but we’re finding out more and more about what goes on in the body and the brain when we make these decisions.
Do our bodies really crave foods that contain nutrients we need?
Yes, seeking out or craving certain foods can sometimes be the sign of an imbalance within the body as a result of nutrient deficiencies. For example, when our blood glucose (sugar) levels drop because we haven’t eaten in a while, we are likely to crave sugary foods to boost them back up. People with iron deficiency and/or anaemia may crave “haem-based foods” such as meats, and endurance athletes who train for many hours in a day and lose a lot of fluids through sweat are likely to crave salty foods in order to replace the electrolytes lost.
This, however, is not the only reason our body craves certain foods. Other reasons why cravings occur include:
DNA
Individual food preferences have a lot to do with a person’s upbringing: Chances are if you’re exposed to something as a young child, you’ll be less averse to it as an adult. Research has shown that people’s preferences for foods like coffee, artichokes, bacon, dark chocolate, blue cheese, and broccoli, are linked to variants in different specific genes. This is similar to salt as well.
Stress
We tend to crave more sugary and/or salty foods when we’re anxious, overworked or stressed. An explanation for this is because our taste buds are actually primed to appreciate them more during these states. Taste cells on the tongue contain receptors for hormones called glucocorticoids, which are activated during periods of stress. The highest concentration of glucocorticoids are in taste cells for sweet, umami, and bitter tastes, suggesting that we may actually perceive these differently and appreciate them more during periods of stress.
Sight, Sound, and Smell
It’s well known that colour and appearance of foods can affect our taste perception. Furthermore, environmental sights and sounds are also believed to influence your cravings as well. Locations such as grocery stores, restaurants, retail stores, and even your own home could play a role in what you crave.
Hormones
Leptin resistance – Leptin is a hormone produced in your fat tissue. Its primary role is to stimulate your appetite. Regulation of this hormone is normal when your stomach and your brain are in sync. But, the problem starts when constant surges of leptin trick your brain into feeling hungry, even when you’re not. The major cause of this is having too much body fat – carrying more fat means more leptin is produced. Another cause is eating a diet high in sugar and processed carbohydrates. The sugar triggers your fat cells to release surges of leptin.
Low levels of serotonin – Serotonin is your “feel-good” hormone. The neurotransmitter is produced mainly in the gut and is directly linked to our mood, appetite and digestion. Eating carbohydrates and sugar increases the release of serotonin, making us feel fantastic (temporarily). So, when our levels of serotonin are low, our brain tells us that a sugary or carbohydrate-based snack will fix the problem.
For females, as your body’s oestrogen levels fall in weeks three and four of your cycle, levels of serotonin also fall, while cortisol (our stress hormone), increases. This may leave you feeling cranky with heightened PMS symptoms and hunger.
We do we generally crave junk foods — e.g. simply because it tastes good?
The answer to this question lies in the brain. Fatty and sugary foods release two important chemicals in the brain called opioids and dopamine. The opiads are released into the blood stream and bind to receptors in our brains, which give us feelings of pleasure and even mild euphoria. These are also the same opioids that are activated by alcohol, sex, heroin and other drugs. Dopamine is also what motivates us to eat in the first place. Its job is to build our anticipation of food and triggers us to remember, and then look for those foods we love.